Service Manual

78
4.2. Installation Step
The installing steps are reverse to those for
removal.
Carry out checks for system evacuating, keep
pressure, antifreeze leakage.
Check if the radiator is blocked. If the radiator
is blocked, utilize the compressed air to clean
it.
III. Troubleshooting
Types of pressure deviation Possible causes Method for troubleshooting
1. The pressure at the high pressure side
remains unchanged or just slightly rises
(compared with the value when the
engine stalls); the pressure at the low
pressure side is within or under the
range as shown; the air conditioner is
under refrigeration.
2. The pressure at the high pressure side is
normal; the pressure at the low pressure
side is within the range as shown; the
air conditioner is under refrigeration.
Lack of refrigerant or
the expansion valve
fails
Evacuate the refrigerant
● If the volume of the refrigerant is normal
1. Replace the expansion valve
2. Refill the refrigerant to the system
3. Test the pressure again
● If the volume of the refrigerant is short
1. Check if there is leaking, if there is
fix it
2. Refill the refrigerant to the system
3. Test the pressure again
The pressure at the high pressure side is
higher than the specified value; the pressure
at the low pressure side falls rapidly to within
or under the range as shown; the air
conditioner is under refrigeration.
The blockage or
throttling occur
somewhere in the
refrigerant pipelines
The expansion valve
fails
Touch the pipelines to feel the temperature
change
● If there exists temperature differences on
several parts of a certain component
1. Utilize the compressed air and nitrogen
gas to dredge the pipeline and replace the
expansion valve
2. Replace the parts blocked
● If no trouble found
1. Dredge the pipelines with compressed
air and nitrogen
2. Test the pressure again
Initially, the pressures at the high and low
pressure sides are normal, but after a period
of time, the pressure at the high pressure side
is higher than the specified value and the
pressure at the low pressure side is within or
The expansion valve
fails
There exists vapor in
the refrigerant pipelines
Check for dirt or rust in the expansion valve
and replace it when necessary
● Dredge the pipelines with compressed
air and nitrogen